An indoor unit which is disposed by being suspended from the ceiling and which is capable of blowing out air in four directions is known in the prior art (for example, Patent Document 1). The indoor unit disclosed in Patent Document 1 comprises a casing, a heat exchanger and a fan disposed inside the casing. The casing has a rectangular parallelepiped shape (a rectangular shape in bottom plan view). An air outlet port for blowing out air laterally is provided in each side (each side wall) of the casing.
In the indoor unit of Patent Document 1, one of four corner portions of the rectangular-shaped casing is provided with a piping space in which a refrigerant pipe connected to the heat exchanger, a drain pump, a drain pipe, and the like, are arranged. In contrast to a ceiling-embedded unit, virtually the whole of a ceiling-suspended indoor unit is exposed inside the room, and therefore, it is necessary to accommodate refrigerant pipes, drain pipes, and the like, inside the casing, from a design perspective. Therefore, the corner cover which covers the piping space is inevitably large, compared to the other three corner covers.
In an indoor unit of this kind, the two air outlet ports situated on both sides of the corner cover covering the piping space are smaller than the other air outlet ports, due to the restrictions imposed by the corner cover. Therefore, a problem arises in that the air flow volume blowing out from the four air outlet ports varies. Therefore, the blow distance of the air flow blown out from the air outlet ports having low air flow volume is reduced. In an indoor unit of this kind, in order to improve the balance of air flow volumes, for example, countermeasures are envisaged in which members (shutters) for closing off one portion of the air outlet ports having a large opening dimension, are disposed separately in those air outlet ports.
Furthermore, another possible countermeasure is to provide a dividing plate at a prescribed position as described in Patent Document 1. In Patent Document 1, by disposing a dividing plate and providing an air guiding path for guiding the air, variations in the air flow volume from the four air outlet ports is suppressed.
However, with each of the countermeasures described above, there is an increase in the number of components, because members such as a shutter and dividing plate, and the like, need to be provided separately. On the other hand, in place of adopting countermeasures such as adding separate members, if the sizes of the four air outlet ports are made the same, due to the size of the corner cover which covers the piping space and the size of the other three corner covers being made the same, then the opening dimensions of the respective air outlet ports become excessively small.
Patent Document 1: Japanese Patent Application Publication No. H10-103702